Nuclear spin resonance spectroscopy (NMR spectroscopy, Nuclear Magnetic Resonance) is a frequently employed method of examining the electronic environment of individual atoms and the interactions of atoms with one another. This method is based on what is called magnetic nuclear spin resonance. This describes a resonant interaction between the magnetic moment of atomic nuclei present in a strong static magnetic field with a high-frequency magnetic alternating field. In this interaction, the atomic nuclei of a material sample absorb and emit electromagnetic alternating fields in a constant magnetic field. On the basis of characteristic frequency shifts in the spin precision caused by the magnetic moment of the nuclear spin, it is possible, for example, to conclude the binding state of particular isotopes in organic molecules. Nuclear spin resonance spectroscopy is capable in principle of detecting any organic compounds. However, the only isotopes amenable to spectroscopy are those which, in the ground state, have a non-zero nuclear spin and hence a magnetic moment. These include, for example, 1H and 13C. On application of a static magnetic field, magnetic moments precess with a frequency which is characteristic of the particular atom and generally varies within a range between kHz and MHz. They thus emit a magnetic alternating field in the region of a few pT. Since the frequency of the alternating field, as well as the type of atom, is also dependent on the binding state of the atom, the binding states of the atom lead to frequency shifts in the region of a few Hz to 1000 Hz. Because of the limited sensitivity of magnetic field sensors, practical implementation is currently only possible with very large magnetic fields in order to polarize a sufficiently large number of spins that a sufficiently high measurement signal can be obtained with appropriate pulse excitation. The required magnetic fields, which have to reach up to 10 T, can be provided, for example, with superconducting magnets which are cooled with liquid nitrogen. For this reason, miniaturization of NMR instruments is generally impossible.
International patent application WO 2012/016977 A2 is concerned with a process for producing an optical element based on diamond. One possible application described for such an optical element is a magnetometer.